So same thing, next cycle. Thought maybe it was my soap, just washed it well with water and boiled it a few times (meant to go get different soap but never got around to it). Same thing... burning/ itching like I'm getting a yeastie, but one never starts.
The itching often goes away maybe 6 hours into using it, then restarts when I change it out after 12 hours. I've had other silicone things in my vagina (diaphragm, male/ female condoms) with no problems (latex does make me itch, though). I've certainly had my fingers in that area before, even after washing with my regular bathroom soap. I've never had itching from sex (except when I have a yeast infection). Never had itching from tampons, and you'd think they're more irritating!
Ideas? Could I possibly be allergic? Is there another brand that would be better? I LOVE this cup and I don't want to go back to tampons, but the itch is killing me! Not enough to keep me up at night, but almost (like the pre-yeast infection itch).